Transfer, by conjugation and transduction, of resistance to ceftazidime and cefotaxime from the same clinical isolate of Pseudomonas aeruginosa.

A strain of Pseudomonas aeruginosa No. 4870 was isolated at the Pediatric University Hospital in Bratislava which transferred, by conjugation, the resistance to cefotaxime (CTX), ceftazidime (CTZ) and aztreonam (AZA) and to more classical anti-pseudomonadal antibiotics. This strain was also lysogenic and contained a temperate bacteriophage which was isolated and used to transduce determinants of resistance to susceptible P. aeruginosa strains. The phage, designated as AP-271 (Aeruginosa phage) transduced determinants of resistance to CTX CTZ AZA as well as to kanamycin and, in one case, also to streptomycin to four susceptible recipient strains of PAO and ML series. The block of resistance to three new betalactam drugs was not separated by transduction. Results obtained indicate that both conjugation and transductional transfer of antibiotic resistance from the same strains of P. aeruginosa seem to be possible.